Greetings,

Want to double check that this is a fair deal

Glock 19 w/4 mags + $350 for a century R1A1, 10 mags, 100 rounds of Yugo .308. He says it functions great, has a nice scope on it to.

Looking for guidance.

I wouldn't do it.

The rifle MAY be one of the good ones or a total cluster-fuck, depending on which Angry Beaver assembled it that day. 10 mags are worth $150 tops, and the Yugo ammo is probably the light-blue boxed S&B, which means that it has very hard primers and is corrosive. Unless the scope mount is a DSA then it may or may not retain a decent zero, so count the scope and mount as "freebies" and not value-added items.

I'd offer a straight swap of G19+ 4 mags for the rifle and extras. You at least know that your Glock is reliable, something that can't always be said about Century FALs. Don't be afraid to drive a hard bargain, as there is nothing in the deal from his end that stands out as a particularly good deal.

keep your glock, put $350 twards a better rifle.

I would stay away for anything Century.  Century firearms are parts kits built on cheap receives by crackheads.

Yes Century builds can be problematic....but If you know/trust the guy and were to trade...I would do glock + $100
It would be ideal to test fire the rifle first.
YMMV

Couldn't have said it any better myself